Door sash and method for manufacturing same

ABSTRACT

A method for manufacturing a door sash formed from a single plate material includes: a roll-forming step of providing a gap portion between the plate materials forming a stepped section and roll-forming a periphery of an end portion of a plate material extending from a tubular section, so as to come into contact along the plate material forming the stepped section; a press working step of pressing the end portion of the plate material to a position where the end portion does not protrude further toward the side on which a weather strip is fitted than a surface of an overlapping section and a surface of the tubular section on the side on which the weather strip is fitted, while crushing the gap portion; and a welding step of continuously laser-welding the overlapping section along a longitudinal direction of the door sash.

The application is a divisional application of U.S. Ser. No. 15/508,260dated Mar. 2, 2017, now U.S. Pat. No. 10,464,404. ApplicationPCT/JP2015/069537 claims priority from Application 2014-180126 filed onSep. 4, 2014 in Japan. The entire contents of these applications areincorporated herein by reference in their entirety.

Also, this application is related to co-pending application: “DOOR SASH”filed Mar. 2, 2017 in the name of Ryota Noguchi as a national phaseentry of PCT/JP2015/069538, which application is assigned to theassignee of the present application and is incorporated by referenceherein.

TECHNICAL FIELD

The present invention relates to a door sash which is used for a windowframe or the like of a door of an automobile, and a method formanufacturing the door sash.

BACKGROUND ART

A door sash which is used for a window frame or the like of a door of anautomobile is generally provided to be roll-formed into the shape shownin FIG. 5 from a plate material which is a single metal strip. A doorsash 1 shown in FIG. 5 is configured of an overlapping section 2 inwhich plate materials are overlapped each other and welded to each otheralong a longitudinal direction, a tubular section 3 formed at one endportion of the overlapping section 2 and having a substantially D-shapewhen viewed in a cross section, flange sections 4 and 5 respectivelyformed to protrude from the other end portion of the overlapping section2 to both sides, and a holder 6 which is provided on the side oppositeto the tubular section 3 with respect to the overlapping section 2 andformed by curving an end portion of the plate material into asubstantially semicircular shape.

Further, a glass channel (not shown) is fitted between the tubularsection 3 and the flange section 4 protruding downward in FIG. 5, thatis, toward a window glass W side. On the other hand, a weather strip 7is fitted between the holder 6 and the flange section 5 protrudingupward in FIG. 5, that is, toward a vehicle main body B side. When theweather strip 7 is fitted, a projection portion 5 a of the flangesection is fitted into a recess portion 7 a of the weather strip 7 andthe holder 6 is fitted into a recess portion 7 b of the weather strip 7.PTL 1 discloses the same type of door sash.

CITATION LIST Patent Literature

[PTL 1] JP-A-8-104139

SUMMARY OF INVENTION Technical Problem

However, in the door sash 1 shown in FIG. 5, a gap 8 is formed between apart where the plate materials of the overlapping section 2 doublyoverlap each other and the holder 6. The gap 8 is a portion which isexposed to the outside, and therefore, water tends to stagnate in thegap 8, and the water penetrates between the plate materials configuringthe overlapping section 2 due to capillarity, thereby causing theoccurrence of rust. In order to prevent the occurrence of such rust, itis necessary to seal the gap 8 by applying a seal material to the gap 8along the longitudinal direction of the door sash 1. However, since astep of applying the seal material is added, the effectiveness of amanufacturing process is impeded, and since the gap 8 is a portion towhich a coating material does not easily adheres, labor is required toreliably apply the seal material.

Furthermore, various shapes other than the shape shown in FIG. 5 existin the weather strip 7, and for example, there is also a shape withoutthe recess portion 7 b. When fitting the weather strip 7 having such ashape into the door sash 1, it is necessary to cut away the holder 6 ofthe door sash 1. However, if a cut end portion remaining on the doorsash 1 side in a case of cutting away the holder 6 protrudes furthertoward the side on which the weather strip 7 is fitted than a surface 2a of the overlapping section 2 or a surface 3 a of the tubular section 3on the side on which the weather strip 7 is fitted, the cut end portioninterferes with the weather strip 7, and a gap is formed between thedoor sash 1 and the weather strip 7, so that close contact between thedoor sash 1 and the weather strip 7 decreases. Further, cutting theholder 6 into a shape in which the cut end portion does not protruderequires complicated work.

The present invention is proposed in consideration of the above problemand provides a door sash in which the occurrence of rust can beprevented and close contact with a weather strip is improved, and amethod for manufacturing the door sash.

Solution to Problem

In order to solve the above problem, according to an aspect of thepresent invention, there is provided a method for manufacturing a doorsash which is formed from a single plate material and includes anoverlapping section formed by making the plate materials overlap eachother, a stepped section which extends from a car-interior-side endportion of the overlapping section and is bent toward the side on whicha window glass is disposed, such that a step is formed, a tubularsection formed to extend from the stepped section, and flange sectionsrespectively formed to protrude from a car-exterior-side end portion ofthe overlapping section to both sides, the method including: aroll-forming step of roll-forming a periphery of an end portion of theplate material extending from the tubular section, so as to come intocontact along the plate material forming the stepped section, whileproviding a gap portion between the plate materials forming the steppedsection; a press working step of pressing the end portion of the platematerial to a position where the end portion does not protrude furthertoward the side on which a weather strip is fitted than a surface of theoverlapping section and a surface of the tubular section on the side onwhich the weather strip is fitted, such that the gap portion is crushedby the end portion of the plate material; and a welding step ofcontinuously laser-welding the overlapping section along a longitudinaldirection of the door sash.

With this configuration, it is possible to manufacture a door sash inwhich the occurrence of rust can be prevented and close contact with theweather strip is improved.

Further, in the method for manufacturing a door sash according to theabove aspect of the present invention, the welding step is to weld aplace close to a center of gravity of a cross section orthogonal to thelongitudinal direction of the door sash.

With this configuration, it is possible to manufacture a door sash withimproved bending resistance properties.

Further, according to another aspect of the present invention, there isprovided a door sash which is formed from a single plate material and inwhich a weather strip is fitted, including: an overlapping sectionformed by making the plate materials overlap each other; a steppedsection which extends from a car-interior-side end portion of theoverlapping section and in which a step bent toward the side on which awindow glass is disposed is formed; a tubular section formed to extendfrom the stepped section; and flange sections respectively formed toprotrude from a car-exterior-side end portion of the overlapping sectionto both sides, in which a periphery of an end portion of the platematerial extending from the tubular section is formed so as to come intocontact along the plate material forming the stepped section, a gapportion formed between the plate materials forming the stepped sectionis crushed by the end portion of the plate material, and the end portionof the plate material is formed at a position where the end portion doesnot protrude further toward the side on which the weather strip isfitted than a surface of the overlapping section and a surface of thetubular section on the side on which the weather strip is fitted.

With this configuration, it is possible to prevent the occurrence ofrust and improve close contact with the weather strip.

Further, in the door sash according to the above aspect of the presentinvention, the overlapping section is welded at a place close to acenter of gravity of a cross section orthogonal to a longitudinaldirection of the door sash.

With this configuration, the bending resistance properties of a weldedplace are improved.

Advantageous Effects of Invention

According to the method for manufacturing a door sash according to theabove aspect of the present invention, it is possible to manufacture adoor sash in which the occurrence of rust is prevented and close contactwith the weather strip is improved. Further, according to the door sashaccording to the above aspect of the present invention, it is possibleto prevent the occurrence of rust and improve close contact with theweather strip.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1(a) is a cross-sectional view of a door sash according to anembodiment, and FIG. 1(b) is a cross-sectional view showing a statewhere a weather strip is mounted on the door sash shown in FIG. 1(a).

FIG. 2(a) to 2(c) are schematic diagrams for describing a manufacturingprocess of the door sash according to the embodiment.

FIG. 3 is a partial enlarged view of a portion A shown in FIG. 2(a).

FIG. 4 is a side view showing an example of a vehicle door with the doorsash according to the embodiment applied thereto.

FIG. 5(a) is a cross-sectional view of a door sash according to anexample of the related art, and FIG. 5(b) is a cross-sectional viewshowing a state where a weather strip is mounted on the door sash shownin FIG. 5(a).

DESCRIPTION OF EMBODIMENTS

Hereinafter, a door sash according to an embodiment of the presentinvention will be described in detail based on the accompanyingdrawings. FIG. 1(a) is a cross-sectional view of the door sash accordingto the embodiment of the present invention, and FIG. 1(b) is across-sectional view showing a state where a weather strip is mounted onthe door sash shown in FIG. 1(a).

A door sash 10 of this embodiment configures a vehicle door 100 of anautomobile, as shown in FIG. 4. The vehicle door 100 opens and closes adoor opening of a vehicle main body B and has a door main body 101, andthe door sash 10 which forms an opening, in which a window glass W movesup and down, in an upper part of the door main body 101. Thecross-sectional view shown in FIG. 1 shows a cross-sectional shape inline A-A shown in FIG. 4.

The door sash 10 of this embodiment is formed of a metal strip which isa single plate material, and a weather strip is fitted therein. As shownin FIG. 1, the door sash 10 has an overlapping section 11 formed bymaking the plate materials overlap each other, a stepped section 12which extends from a car-interior-side end portion (an end portion in adirection of an arrow X) of the overlapping section 11 and is benttoward the side on which the window glass W is disposed (the lower sidein FIG. 1), such that a step is formed, a tubular section 13 formed toextend from the stepped section 12, and flange sections 14 and 15respectively formed to protrude from a car-exterior-side end portion (anend portion in a direction of an arrow Y) of the overlapping section 11to both sides.

The overlapping section 11 has a configuration in which plate materials19 a and 19 b doubly overlap each other. Specifically, the overlappingsection 11 has a configuration in which the plate material 19 a whichextends so as to be connected from the flange section 14 protrudinglaterally on the side on which the window glass W is disposed, to thetubular section 13 through the stepped section 12, and the platematerial 19 b which extends toward the tubular section 13 from theflange section 15 protruding laterally on the side on which a weatherstrip 17 is fitted, and forms an end portion at the stepped section 12,overlap each other.

The stepped section 12 has a configuration in which a plate material 19c extending toward the flange section 15 from the tubular section 13additionally overlaps the plate material 19 a and the plate material 19b. In this embodiment, the plate materials 19 a and 19 b are bent towardthe side on which the window glass W is disposed, whereby the steppedsection 12 is formed, and the periphery of an end portion 16 a of theplate material 19 c is formed so as to come into contact with the platematerial 19 b forming the stepped section 12. Further, the end portion16 a of the plate material 19 c is a cut end portion remaining after aholder (not shown) is cut away in order to fit the weather strip 17 intothe door sash 10.

The tubular section 13 is formed in a substantially D-shape when viewedin a cross section. A glass channel (not shown) is fitted between thetubular section 13 and the flange section 14. On the other hand, theweather strip 17 is fitted on the flange section 15 side. The weatherstrip 17 has a recess portion 17 a formed on the side on which theweather strip 17 comes into contact with the flange section 15, and therecess portion 17 a is fitted to a projection portion 15 a formed toprotrude at the flange section 15. Further, the weather strip 17 isfixed to the tubular section 13 by using a mounting clip 18. With thisconfiguration, the weather strip 17 is fixed to the door sash 10.

The end portion 16 a of the plate material 19 c is formed at a positionwhere the end portion 16 a does not protrude further toward the side onwhich the weather strip 17 is fitted than a surface 111 of theoverlapping section 11 and a surface 131 of the tubular section 13 onthe side on which the weather strip 17 is fitted. For example, the endportion 16 a is subjected to press working in a direction of an arrow Zshown in FIG. 2(b), thereby being formed at a position where it does notprotrude further toward the side on which the weather strip 17 is fittedthan the surface 111 of the overlapping section 11 and the surface 131of the tubular section 13. The deformation amount of the end portion 16a due to press working is entirely absorbed due to a gap portion S shownin FIG. 3, which is formed between the plate materials 19 a and 19 bforming the stepped section 12, being crushed by the end portion 16 a ofthe plate material 19 c, and thus a distortion or the like does notoccur in the overlapping section 11 or the tubular section 13.

Next, a method for manufacturing the door sash 10 according to a firstembodiment will be described hereinafter. First, a metal strip which isa single plate material is passed between plural sets of forming rolls,thereby being roll-formed into a cross-sectional shape shown in FIG.2(a). At that time, as shown in FIG. 3, the gap portion S is formedbetween the plate materials 19 a and 19 b forming the stepped section12. Then, at the final stage of the roll-forming, the plate material 19c forming the surface 131 of the tubular section 13 on the side on whichthe weather strip 17 is fitted is gradually bent, as shown by a two-dotchain line in FIG. 2(a), and the periphery of the end portion of theplate material 19 c is disposed so as to come into contact along theplate material 19 b forming the stepped section 12. With thisdisposition, the stepped section 12 has a configuration in which theplate material 19 a, the plate material 19 b, and the plate material 19c triply overlap each other.

Next, when fitting the weather strip 17 with respect to the door sash10, a holder 16 which becomes unnecessary is cut away. A cut end portionremaining after the cutting of the holder 16, that is, the end portion16 a protrudes further toward the side on which the weather strip 17 isfitted than the surface 111 of the overlapping section 11 and thesurface 131 of the tubular section 13 (refer to FIG. 2(b)). With thisshape as it is, when an attempt to fit the weather strip 17 into thedoor sash 10 is made, the end portion 16 a interferes with the weatherstrip 17.

Therefore, the end portion 16 a of the plate material 19 c is subjectedto press working in the direction of the arrow Z shown in FIG. 2(b) to aposition where the end portion 16 a does not protrude further toward theside on which the weather strip 17 is fitted than the surface 111 of theoverlapping section 11 and the surface 131 of the tubular section 13 onthe side on which the weather strip 17 is fitted. At that time, the endportion of the plate material is subjected to press working such thatthe gap portion S shown in FIG. 3 is crushed by the end portion 16 a ofthe plate material 19 c. The end portion 16 a of the plate material 19 csubjected to press working does not protrude further toward the side onwhich the weather strip 17 is fitted than the surface 111 of theoverlapping section 11 and the surface 131 of the tubular section 13 onthe side on which the weather strip 17 is fitted, as shown in FIG. 2(c),and does not interfere with the weather strip 17. The deformation amountof the end portion 16 a due to press working is absorbed by thedeformation of the stepped section 12, and therefore, a distortion orthe like does not occur in the overlapping section 11 or the tubularsection 13.

Then, the overlapping section 11 is continuously laser-welded along thelongitudinal direction of the door sash 10, that is, in a directionperpendicular to FIG. 1. It is preferable if the welded place is weldedat a predetermined place of the overlapping section 11 close to thecross-sectional center of gravity of a cross section orthogonal to thelongitudinal direction of the door sash 10, for example, at the steppedsection 12. Here, the cross-sectional center of gravity of a crosssection orthogonal to the longitudinal direction of the door sash 10 canbe calculated in advance by using CAD software such as Auto-CAD, or thelike. By being welded at a place close to the cross-sectional center ofgravity, it becomes possible to improve the resistance properties in abending direction of the welded place.

Thereafter, a glass channel (not shown) is fitted and mounted betweenthe tubular section 13 and the flange section 14. Further, the recessportion 17 a of the weather strip 17 is fitted to the projection portion15 a formed to protrude at the flange section 15, and the weather strip17 is fixed to the tubular section 13 by using the mounting clip 18,thereby being fixed to the door sash 10.

In the door sash 10 of this embodiment and the method for manufacturingthe door sash 10, the gap 8 formed in the door sash 1 of the related artis not formed, and therefore, a configuration in which water does notpenetrate between the plate materials 19 a and 19 b of the overlappingsection 11 is made, and thus the occurrence of rust can be prevented.

Further, in the door sash 10 of this embodiment and the method formanufacturing the door sash 10, the end portion 16 a remaining after thecutting of the holder 16 is formed at a position where it does notprotrude further toward the side on which the weather strip 17 is fittedthan the surface 111 of the overlapping section 11 and the surface 131of the tubular section 13 on the side on which the weather strip 17 isfitted, and therefore, when the weather strip 17 is fitted into the doorsash 10, the end portion 16 a does not interfere with the weather strip17, and thus the close contact between the weather strip 17 and the doorsash 10 can be improved. Further, in the door sash 10 of this embodimentand the method for manufacturing the door sash 10, the deformationamount of the end portion 16 a due to press working is entirely absorbeddue to the gap portion S shown in FIG. 3, which is formed between theplate materials 19 a and 19 b forming the stepped section 12, beingcrushed by the end portion 16 a of the plate material 19 c, andtherefore, the outer shape of the door sash 10 is not affected, and adistortion does not occur in the stepped section 12.

Further, in the door sash 10 of this embodiment and the method formanufacturing the door sash 10, it is possible to improve the resistanceproperties in the bending direction of the welded place of the door sash10.

Modification Example and the Like of Embodiment

The invention disclosed in this specification includes, in addition tothe configuration of each invention or embodiment, a configurationspecified by changing partial configurations of the above configurationto other configurations disclosed in this specification, within anapplicable range, a configuration specified by adding otherconfigurations disclosed in this specification to the aboveconfiguration, or a configuration specified to a high-level concept bydeleting partial configurations of the above configuration to the extentthat a partial operation and effect can be obtained.

REFERENCE SIGNS LIST

-   -   10: door sash    -   11: overlapping section    -   12: stepped section    -   13: tubular section    -   14, 15: flange section    -   15 a: projection portion    -   16: holder    -   16 a: end portion    -   17: weather strip    -   17 a: recess portion    -   18: mounting clip    -   19 a, 19 b, 19 c: plate material    -   100: vehicle door    -   101: door main body    -   B: vehicle main body    -   W: window glass

The invention claimed is:
 1. A method for manufacturing a door sash which is formed from a single plate material and includes an overlapping section formed by making the plate material overlap each other, a stepped section which extends from a car-interior-side end portion of the overlapping section and is bent toward a side on which a window glass is disposed, such that a step is formed, a tubular section formed to extend from the stepped section, and flange sections respectively formed to protrude from a car-exterior-side end portion of the overlapping section to both the side on which the window glass is disposed and a side on which a weather strip is fitted, the method comprising: a roll-forming step of roll-forming a periphery of an end portion of the plate material extending from the tubular section, so as to come into contact along the plate material forming the stepped section, while providing a gap portion between the plate material forming the stepped section; a press working step of pressing the end portion of the plate material to a position where the end portion does not protrude further toward the side on which the weather strip is fitted than a surface of the overlapping section and a surface of the tubular section on the side on which the weather strip is fitted, such that the gap portion is crushed by the end portion of the plate material; and a welding step of continuously laser-welding the overlapping section along a longitudinal direction of the door sash.
 2. The method for manufacturing a door sash according to claim 1, wherein the welding step is to weld a place close to a center of gravity of a cross section orthogonal to the longitudinal direction of the door sash. 